“The pain is so intense, I can’t make it go away,” Jigna Howland said. “I can’t make the vomiting stop.”

The sickness is called cannabinoid hyperemesis syndrome, known as CHS, and it’s linked to chronic marijuana use. It’s so new that there are no hard numbers on how many people are affected across the country. Doctors believe using large amounts of marijuana frequently triggers a painful vomiting syndrome -- but only in certain people.

“Who has this condition, what brings it on and how can we help them?” Dr. Sean Bozorgzadeh said.

One of his patients was Jigna Howland, who, over the past few years, started battling what seemed like a strange, unexplained illness.

“You are literally just retching and retching, and it’s painful,” she said.

Howland has smoked pot for decades and uses it daily, in part to combat high blood pressure and anxiety. She’s also worked at Cannazone cannabis store in Mount Vernon, Washington, since it opened earlier this year. But she could not figure out what suddenly started causing the sickness.

“I had no idea what was going on, other than I was getting sick once a year -- and it was a pretty heavy illness,” she said.

She received medical treatment five times. Doctors told her tests were inconclusive.

Then, four months ago, doctors at Peace Health United General in Sedro-Woolley, Washington, suggested pot might be at the root of it.

“Right now, we see one or two a day, almost ... It’s much more common,” he said.

KIRO-TV’s investigation led to other cities and hospitals. At Providence St. Peter Hospital in Olympia, Washington, doctors reported seeing one to two cases a week. Harborview Medical Center sees one to two cases a month. as does Virginia Mason Hospital and Medical Center.

Overlake Hospital Medical Center reports seeing a case every two to three months, and Swedish Hospital told KIRO-TV it sees CHS cases “often,” but did not offer more details.

Dr. Otto Lin at Virginia Mason co-authored a case study of a man who reported “vomiting for 16 years,” while he struggled with the undiagnosed sickness, all the while “consuming at least four to eight marijuana doses (joints) per day.”

CHS is gaining national attention, too. People across the country have started speaking out, and a recent story in The Atlantic asked in the headline, "Will Smoking Pot Make Me Vomit Forever?"

It is still unclear how and why pot has this effect on certain people. However, Bozorgzadeh pointed out, “We do know that people who use it chronically and they use a lot of it, you know, sometimes three to five times a day, are more prone to developing this.”

Once patients are treated with IVs and medication, doctors say the symptoms usually stop after a couple of days. Then Bozorgzadeh recommends a trial phase of no pot at all.

“So they go through a period of time where they do not smoke cannabis, and if the condition improved or went away, that's proof that it's causing it,” he said.

Howland switched for a while to marijuana products with low levels of THC, the psychoactive chemical in pot that gets people high. She now smokes fewer concentrates, which she personally believes may have helped trigger the sickness for her in the first place.

“Some people refuse to believe it,” she said. “They think it's a very anti-marijuana stance. It is not anti-marijuana. It’s how I make my living—is selling marijuana. I enjoy marijuana. There is nothing wrong with it. It just comes back to moderation.”